Khaled Aedh Alotaibi was arrested at Charles de Gaulle airport in Paris on Tuesday, a police source told the BBC.
He is believed to be one of 26 Saudis wanted by Turkey over the killing.
A Saudi official later said the arrest was a case of mistaken identity, and that those involved in the murder had been convicted in Saudi Arabia.
Mr Alotaibi, a 33-year-old former Saudi royal guard, was travelling under his own name and was placed in judicial detention, RTL radio said.
